Download Jeff Errington L-form bacteria: life without walls or a division machine

Jeff Errington
L-form bacteria: life without walls or a division machine
The peptidoglycan cell wall is a defining feature of bacterial cells. It has a wide range of important
functions and is usually essential for cell viability. It is the target for our best antibiotics and
fragments of the wall are recognised as danger signals by our innate immune systems. The wall was
probably present in the last common ancestor of the bacteria and thus in the first recognisable cells
on earth. It is thus shocking that many bacteria seem to be able to switch almost effortlessly into a
cell wall deficient state, given only a couple of genetic changes and an isotonic environment. We
have developed model systems to study these organisms and what we have learned about their
remarkable properties in the last 5 or so years will be reviewed. Among the surprises have been that
L-forms become completely independent of the normally essential FtsZ-based division machinery,
and that they reproduce instead by a blebbing or tubulation-fission mechanism involving only
membrane dynamics. Recent advances in understanding some of the broader implications of L-form
biology, including implications for the origins of life will be discussed.
Key references
Leaver M, Dominguez-Cuevas P, Coxhead JM, Daniel RA, Errington J. (2009) Life without a wall or
division machine in Bacillus subtilis. Nature 457, 849-853.
Mercier R, Kawai Y, Errington J. (2013) Excess membrane synthesis drives a primitive mode of cell
proliferation. Cell152, 997-1007.
Kawai Y, Mercier R, Errington J. (2014) Bacterial cell morphogenesis does not require a pre-existing
template structure. Current Biology (online).